- Joined
- Jan 12, 2009
- Location
- Liberty Twp., Ohio
So you wanna add a JACK PLATE to your boat…………………
Before you go out and buy yourself a Jack Plate, consult your dealer to see what the transom of your boat will tolerate and if your warranty allows adding a J/Plate. Most all glass boats will accept a 6" Jack Plate. It's the 8" to 15" plates you need to know about because of the tremendous load they place on you transom. Then talk to people that have the same or near the same boat/motor combination as yours to help you narrow down which plate you'll need. There is no magic formula that says boat brand "XXX" works best with an XX inch plate. I started out with a 6" plate just because I had to have one and didn't know any better at the time, worked out pretty good, but later found out through talking to others with a similar boat/motor I needed a 10" plate. What a difference that plate change from 6" to 10" made, that's why you need to do your homework first, it'll save you some money as well.
If you've just bought yourself a Jack Plate and wondering how the hell am I gonna get that baby on there.................Here's some tips for a safe DIY install.
1. Before you even think about pulling the motor, check to ensure that you have enough slack in your steering cable(s) or Hyd. Hoses. You don't want either of these to go into any sort of bind or tight radius bend. Your safety/life depends on this being checked (before and after the install).
2. Check your wiring harness & throttle & shift cables for enough slack as well, don't want a bind on either one of those. (there is unusually enough slack for a 6" plate on most boats)
3. Using a proper lifting eye for your motor and a standard automotive type engine puller, put a slight lifting load on the motor, key word is slight. Option for those who don't have the proper lifting eye for there motor; it is possible to lift the motor using straps in the front and rear of the block to balance the lift, but use extreme caution as this method is a disaster waiting to happen. Use the proper tools and methods, you'll be around to fish another day !!!!
4. Loosen the four 1/2" bolts holding the motor on the transom until the motor is loose from the transom.
Note: Some installers apply the sealant heavy around the 1/2" bolts holes, so you made have to wiggle the motor a bit to get it broken free from the transom, may even require you to use a putty knife (carefully) between the motor and transom to loosen the seal.
5. Once the motor is loose and free of any sealant holding it in place. Raise the motor enough to allow the removal of all bolts freely. Remove all 4 bolts.
6. Once ,motor is removed (leave it hang on the lift out of your way, careful when you move it not to damage cables/hoses) you must clean the transom of any and all residual sealant to ensure a good flat fit of your new Jack Plate. Use care and caution as not to scratch the Gel Coat surface. Try to remove as much sealant as possible from inside the holes as well.
7. Here's an important step nobody tells you about, but you'll see the problem after your completely finished with your install.
Not all boats are created equal. Due to mass production methods, I have seen transom mounting holes off as much as 1/2" from being level. This obviously mounts your motor at an angle and not straight up and down on the transom.
(A) Use a 2 to 4 ft level and get your boat leveled up side to side. Use a floor jack under the trailer to accomplish this task. Place the level on the deck behind the seats or across the entire width of the boat aft of the seats if you have a big enough level.
8. Use a 2 foot level and place the level against the transom under the top two holes. Align the hole bottom edge with the level's top surface. You should have a level reading, do this again on the lower two holes to verify everything is good to go.
(If it's not level):
You have options to correct this,
(1) Elongate the holes that are out of level in the transom……….DON'T DO THIS NO MATTER WHAT !!!!!!!!!
(2) Elongate the holes in the Jack Plate on the motor side, this is a better option if needed because you can apply more torque to your bolts there than going through fiberglass/composite transom. Most of the time, there is enough built up clearance with all the holes to get everything lined up pretty damm close if not exact. So if it's off a little you know where to make a change, on the motor side of the plate.
9. Check your new Jack Plate by having the Jack Plate either fully up or bottomed out fully down. This is more important on a Hyd. Plate than Manual Plate, but never the less, it is important. Now place the J/Plate onto the transom with your mounting bolts, this will be a dry fit. Now the important level check, with the plate just snug up against the transom, place the level on the motor side of the plate and verify that the motor mounting holes in the plate are level. If not loosen the J/Plate from the transom and see if there is enough clearance in those holes. If your still coming up short of level, then you'll attach your J/Plate to the transom in the best possible or closest to level position possible and secure using new mounting bolts, 3M #4200 sealant per the manufactures instructions, torque to spec if so called out. It is important to note that the use of a torque plate be used top and bottom position on the mounting bolts to help distribute the pressure applied when bolts are tightened.
10. Now since your J/Plate is mounted onto your transom and tightened up to manufactures spec's, make any adjustment to the holes (elongate) on the motor side of the J/Plate at this time to ensure a mounting that will keep you motor level. I generally verify the motor is level by placing the level across the top of the flywheel, it's the best flat reference point available. Once you've made any changes needed to your J/Plate motor side mounting holes, deburr them and hang your motor using new mounting bolts, washers and nuts, secure per manufactures recommended torque spec's. I recommend using Loctite-Blue #242 on all 4 motor mounting bolts. It acts as a lubricant and thread locker at the same time.
11. Now verify that there is no bind in your hoses/cables by going through a full right and left turn on the wheel, do this easy. It helps to have a buddy turn the wheel for you and you looking at the hoses/cables. Same applies to the trim on your motor, make sure that you can get full trim (up & down) without putting the hoses/cables into a sever bind. Also watch that your hoses/cable clear the top edge of the transom. Since you've moved your motor back the hoses/cables are no longer going to fold up in the splash well as they did before adding a J/Plate, so check for clearance on everything. If your good to go, set your prop shaft approximately 3 1/2" inches below your pad.
12. Setting prop shaft height; level boat on the trailer (use trailer dolly to level). Use a 2 or 4 ft. level on the bottom of the hull at the transom and adjust till level. Now use a smaller level (torpedo style is easier) and place level on top of prop shaft, adjust trim till prop shaft shows level. Now both the hull and the prop shaft are level and parallel to each other. Place a straight edge or your 4 ft level against the bottom of the hull on it's centerline, have the level or straight edge extend back to meet the nose of your lower unit. The very tip of the nose is the center of the prop shaft. Adjust the J/Plate up or down until your center point on the nose of your lower unit is 3 1/2" below the top edge of the level or straight edge resting on the hulls bottom centerline. Secure your J/Plate, allow the sealent to cure per manufactures recommendations, then head for water to start a day of testing, looking for the ultimate position. Have your boat loaded as you normally have it when going out to fish. Then start to raise the J/Plate 1/2" at a time to find the sweet spot that works best for your set up, hole shot, top speed etc. Best results are obtained using a "GPS" over a boat speedometer and a Water Pressure Gauge. You need exact numbers you can rely on, this is where a GPS & Water Pressure Gauge comes in. You have to monitor water pressure. If you raise the motor to high, the potential of not being able to pick up enough water for cooling is possible.
In summary, please note that this adjustment takes time, lots of trial and error but the results are well worth it and you'll be far happier with your rig and the way it performs. This is a modification that can ruin your life if not done properly, please don't shortcut anything. There is a tremendous amount of force that is being applied to your transom by the motors power and rough water conditions as well. Adding a J/Plate "DOES CHANGE THE BOATS CENTERLINE OF BALANCE" because your moving a heavy object (motor) further aft. This will change ride, handling, attitude of boat sitting in the water etc.
Good luck and be safe..........
Before you go out and buy yourself a Jack Plate, consult your dealer to see what the transom of your boat will tolerate and if your warranty allows adding a J/Plate. Most all glass boats will accept a 6" Jack Plate. It's the 8" to 15" plates you need to know about because of the tremendous load they place on you transom. Then talk to people that have the same or near the same boat/motor combination as yours to help you narrow down which plate you'll need. There is no magic formula that says boat brand "XXX" works best with an XX inch plate. I started out with a 6" plate just because I had to have one and didn't know any better at the time, worked out pretty good, but later found out through talking to others with a similar boat/motor I needed a 10" plate. What a difference that plate change from 6" to 10" made, that's why you need to do your homework first, it'll save you some money as well.
If you've just bought yourself a Jack Plate and wondering how the hell am I gonna get that baby on there.................Here's some tips for a safe DIY install.
1. Before you even think about pulling the motor, check to ensure that you have enough slack in your steering cable(s) or Hyd. Hoses. You don't want either of these to go into any sort of bind or tight radius bend. Your safety/life depends on this being checked (before and after the install).
2. Check your wiring harness & throttle & shift cables for enough slack as well, don't want a bind on either one of those. (there is unusually enough slack for a 6" plate on most boats)
3. Using a proper lifting eye for your motor and a standard automotive type engine puller, put a slight lifting load on the motor, key word is slight. Option for those who don't have the proper lifting eye for there motor; it is possible to lift the motor using straps in the front and rear of the block to balance the lift, but use extreme caution as this method is a disaster waiting to happen. Use the proper tools and methods, you'll be around to fish another day !!!!
4. Loosen the four 1/2" bolts holding the motor on the transom until the motor is loose from the transom.
Note: Some installers apply the sealant heavy around the 1/2" bolts holes, so you made have to wiggle the motor a bit to get it broken free from the transom, may even require you to use a putty knife (carefully) between the motor and transom to loosen the seal.
5. Once the motor is loose and free of any sealant holding it in place. Raise the motor enough to allow the removal of all bolts freely. Remove all 4 bolts.
6. Once ,motor is removed (leave it hang on the lift out of your way, careful when you move it not to damage cables/hoses) you must clean the transom of any and all residual sealant to ensure a good flat fit of your new Jack Plate. Use care and caution as not to scratch the Gel Coat surface. Try to remove as much sealant as possible from inside the holes as well.
7. Here's an important step nobody tells you about, but you'll see the problem after your completely finished with your install.
Not all boats are created equal. Due to mass production methods, I have seen transom mounting holes off as much as 1/2" from being level. This obviously mounts your motor at an angle and not straight up and down on the transom.
(A) Use a 2 to 4 ft level and get your boat leveled up side to side. Use a floor jack under the trailer to accomplish this task. Place the level on the deck behind the seats or across the entire width of the boat aft of the seats if you have a big enough level.
8. Use a 2 foot level and place the level against the transom under the top two holes. Align the hole bottom edge with the level's top surface. You should have a level reading, do this again on the lower two holes to verify everything is good to go.
(If it's not level):
You have options to correct this,
(1) Elongate the holes that are out of level in the transom……….DON'T DO THIS NO MATTER WHAT !!!!!!!!!
(2) Elongate the holes in the Jack Plate on the motor side, this is a better option if needed because you can apply more torque to your bolts there than going through fiberglass/composite transom. Most of the time, there is enough built up clearance with all the holes to get everything lined up pretty damm close if not exact. So if it's off a little you know where to make a change, on the motor side of the plate.
9. Check your new Jack Plate by having the Jack Plate either fully up or bottomed out fully down. This is more important on a Hyd. Plate than Manual Plate, but never the less, it is important. Now place the J/Plate onto the transom with your mounting bolts, this will be a dry fit. Now the important level check, with the plate just snug up against the transom, place the level on the motor side of the plate and verify that the motor mounting holes in the plate are level. If not loosen the J/Plate from the transom and see if there is enough clearance in those holes. If your still coming up short of level, then you'll attach your J/Plate to the transom in the best possible or closest to level position possible and secure using new mounting bolts, 3M #4200 sealant per the manufactures instructions, torque to spec if so called out. It is important to note that the use of a torque plate be used top and bottom position on the mounting bolts to help distribute the pressure applied when bolts are tightened.
10. Now since your J/Plate is mounted onto your transom and tightened up to manufactures spec's, make any adjustment to the holes (elongate) on the motor side of the J/Plate at this time to ensure a mounting that will keep you motor level. I generally verify the motor is level by placing the level across the top of the flywheel, it's the best flat reference point available. Once you've made any changes needed to your J/Plate motor side mounting holes, deburr them and hang your motor using new mounting bolts, washers and nuts, secure per manufactures recommended torque spec's. I recommend using Loctite-Blue #242 on all 4 motor mounting bolts. It acts as a lubricant and thread locker at the same time.
11. Now verify that there is no bind in your hoses/cables by going through a full right and left turn on the wheel, do this easy. It helps to have a buddy turn the wheel for you and you looking at the hoses/cables. Same applies to the trim on your motor, make sure that you can get full trim (up & down) without putting the hoses/cables into a sever bind. Also watch that your hoses/cable clear the top edge of the transom. Since you've moved your motor back the hoses/cables are no longer going to fold up in the splash well as they did before adding a J/Plate, so check for clearance on everything. If your good to go, set your prop shaft approximately 3 1/2" inches below your pad.
12. Setting prop shaft height; level boat on the trailer (use trailer dolly to level). Use a 2 or 4 ft. level on the bottom of the hull at the transom and adjust till level. Now use a smaller level (torpedo style is easier) and place level on top of prop shaft, adjust trim till prop shaft shows level. Now both the hull and the prop shaft are level and parallel to each other. Place a straight edge or your 4 ft level against the bottom of the hull on it's centerline, have the level or straight edge extend back to meet the nose of your lower unit. The very tip of the nose is the center of the prop shaft. Adjust the J/Plate up or down until your center point on the nose of your lower unit is 3 1/2" below the top edge of the level or straight edge resting on the hulls bottom centerline. Secure your J/Plate, allow the sealent to cure per manufactures recommendations, then head for water to start a day of testing, looking for the ultimate position. Have your boat loaded as you normally have it when going out to fish. Then start to raise the J/Plate 1/2" at a time to find the sweet spot that works best for your set up, hole shot, top speed etc. Best results are obtained using a "GPS" over a boat speedometer and a Water Pressure Gauge. You need exact numbers you can rely on, this is where a GPS & Water Pressure Gauge comes in. You have to monitor water pressure. If you raise the motor to high, the potential of not being able to pick up enough water for cooling is possible.
In summary, please note that this adjustment takes time, lots of trial and error but the results are well worth it and you'll be far happier with your rig and the way it performs. This is a modification that can ruin your life if not done properly, please don't shortcut anything. There is a tremendous amount of force that is being applied to your transom by the motors power and rough water conditions as well. Adding a J/Plate "DOES CHANGE THE BOATS CENTERLINE OF BALANCE" because your moving a heavy object (motor) further aft. This will change ride, handling, attitude of boat sitting in the water etc.
Good luck and be safe..........
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